Yogurt

Yogurt is a small MUD client library written in Haskell. It can be downloaded from hackage. Yogurt is a DSL embedded in Haskell. Unlike other MUD clients out there, it doesn't offer its own syntax; instead, it relies on Haskell and naturally offers all Haskell's features. This means full control over what messages are sent, variables with any valid Haskell type, no ambiguity about whether a variable is expanded at hook define time or hook trigger time, no clumsy syntax, et cetera. On the other hand, this means you do not get the ability to change the installed hooks at runtime for free.